komatsu is at least partially correct, and leet is a least partially wrong, as a glance at the Wikipedia article shows. "The interface was originally intended to run exclusively on an optical physical layer...This copper-based version of the Light Peak concept was co-developed by Apple and Intel. Apple registered Thunderbolt as a trademark, but later transferred the mark to Intel, which held overriding intellectual-property rights.["

(Note, this isn't contradicting what Semi On wrote, he's referring to controller chips, not the ports themselves.)

Yes-ish. All Thunderbolt 3 ports (on computers) are also at least USB 3.1 Gen 2 ports in the USB-C form factor because Thunderbolt 3 is explicitly and only an Alternate Mode for USB-C which always includes* USB 3.1 Gen 2 functionality. It is, however, possible to make a TB3 device that only works as a TB3 device and that won't function if plugged into an normal USB-C (non-TB3) port.

* As far as I can tell. I'm not a TB dev, and don't have access to the technical docs, but the official TB 3 FAQ explicitly states it does include 10Gbps USB 3.1, which is USB 3.1 Gen 2.

We even see a decent number of devices/cables with Type-C physical and USB 2.0 signalling. The Nintendo Switch's Pro Controller and included cable are one such example.

Nexus 5X is another example, it's a USB-C connector, USB 2.0 signaling. I think it has the USB-PD though, for fast charging, which is usually implemented on USB3, but of course can be implemented on USB2.

There's a pretty substantial portion of the USB market for which power is the primary use case around USB and data connections are largely irrelevant. People generally get information to their phone wirelessly these days and most will never be connected to a PC or the like.

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I think it has the USB-PD though, for fast charging

It does.

Quote:

which is usually implemented on USB3

USB3 and PD are effectively unrelated specs. You can implement PD over any USBC port, regardless of data link.

There's a pretty substantial portion of the USB market for which power is the primary use case around USB and data connections are largely irrelevant. People generally get information to their phone wirelessly these days and most will never be connected to a PC or the like.

Quote:

I think it has the USB-PD though, for fast charging

It does.

Quote:

which is usually implemented on USB3

USB3 and PD are effectively unrelated specs. You can implement PD over any USBC port, regardless of data link.

I said usually, not required

And by usually, I mean because they're pretty much contemporary specs they'd generally be used together.